Step 4Make sure that the new empty layer is selected.Find the approximate position of the nipple in your image.Using the brush, draw a single circle where the nipple would be. The dimension of the circle should be larger than the nipple, but don't worry too much about it, because we will have to tweak it later.The color of the circle has no importance at all.

Step 8 (iteration)Now, you may find that the size or position of your nipple is not correct.Simply erase the circle that you have created at step 4 and redraw it at a different position, or with a smaller or larger brush. The Smudge tool can also be useful here to adjust the shape of the nipple.Repeat this step and the step 7 until you are satisfied with the result.

Step 9 (optional)When you are satisfied with the shape, position and dimension of the nipple, you may wish do modify the fabric of the cloth to give it a stretched look.With the selection tool, select an area that cover the nipple.